An MRI apparatus is an apparatus which measures an NMR signal generated by atomic nucleus spins forming an object, especially, tissues of a human body, and generates morphologies or functions of the head, the abdomen, and the limbs thereof as two-dimensional or three-dimensional images.
A spatially uniform static magnetic field is necessary in a region in which an NMR signal is measured. This is because the homogeneity of a static magnetic field influences image quality (distortion or luminance unevenness of an image, an SNR, and the like). In order to uniformize a static magnetic field in a measurement region, magnetic field adjustment (shimming) is performed so that a substance (hereinafter, simply referred to as magnetic moment) having a magnetic moment of a predetermined magnitude, such as an iron piece is disposed at a predetermined position. The shimming includes, for example, a method of determining arrangement of a magnetic moment by using singular value decomposition (refer to PTL 1).